/*
 * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
 * (the "License"). You may not use this work except in compliance with the License, which is
 * available at www.apache.org/licenses/LICENSE-2.0
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied, as more fully set forth in the License.
 *
 * See the NOTICE file distributed with this work for information regarding copyright ownership.
 */

package alluxio;

import alluxio.util.network.NetworkAddressUtils;

import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;

import java.net.InetSocketAddress;
import java.util.List;

import javax.annotation.concurrent.ThreadSafe;
import javax.security.auth.Subject;

/**
 * The base class for master clients.
 */
@ThreadSafe
public abstract class AbstractMasterClient extends AbstractClient implements MasterClient {
  /**
   * Identifies the Zookeeper path to use for discovering the master address. This should be null
   * if Zookeeper is not being used.
   */
  protected final String mZkLeaderPath;

  /**
   * Creates a new master client base.
   *
   * @param subject the parent subject
   * @param masterAddress the master address
   */
  public AbstractMasterClient(Subject subject, InetSocketAddress masterAddress) {
    super(subject, masterAddress);
    if (Configuration.getBoolean(PropertyKey.ZOOKEEPER_ENABLED)) {
      mZkLeaderPath = Configuration.get(PropertyKey.ZOOKEEPER_LEADER_PATH);
    } else {
      mZkLeaderPath = null;
    }
  }

  /**
   * Creates a new master client base.
   *
   * @param subject the parent subject
   * @param zkLeaderPath the Zookeeper path holding the leader master address
   */
  public AbstractMasterClient(Subject subject, String zkLeaderPath) {
    super(subject, NetworkAddressUtils.getLeaderAddressFromZK(zkLeaderPath));
    Preconditions.checkState(Configuration.getBoolean(PropertyKey.ZOOKEEPER_ENABLED));
    mZkLeaderPath = zkLeaderPath;
  }

  @Override
  public synchronized InetSocketAddress getAddress() {
    if (mZkLeaderPath == null) {
      return super.getAddress();
    }
    return NetworkAddressUtils.getLeaderAddressFromZK(mZkLeaderPath);
  }

  @Override
  public synchronized List<InetSocketAddress> getMasterAddresses() {
    if (mZkLeaderPath == null) {
      return Lists.newArrayList(super.getAddress());
    } else {
      return NetworkAddressUtils.getMasterAddressesFromZK();
    }
  }
}